1. Field of the Invention
The present invention relates to the decision support of the amount of the production order of a plurality of products using a computer and, particularly, to the decision support of amount of the production order based on demand forecasts for products.
2. Description of the Prior Art
A subject for the decision of amount of the production order for specifying the production volumes of a plurality of products in consideration of profit under restrictions, that is, limited production resources, is called xe2x80x9cproduct mix problemxe2x80x9d which is an important subject for the manufacturing industry. Heretofore, the method of determining amount of the production order by a Simplex method has been employed using only information on product cost and sales. However, as the probability distribution of demand forecast is not taken into consideration in this method, it is impossible to make quantitative evaluation on return and risk, for example, how much is the probability of obtaining a desired profit or how much is the probability of going into the red.
Japanese Laid-open Patent Application No. 9-73491 discloses a technology for computing expected values of inventory cost and sales profit from demand forecast to calculate one production instruction value from these values. However, as this technology outputs only one set of amount of the production order of a plurality of parts, the selection of amount of the production order based on the management strategy of a company is impossible.
In the manufacturing industry, production resources such as production equipment and materials are limited. It is necessary to determine the amount of the production order of a plurality of products in order to obtain the maximum profit from the limited production resources. The manufacturing industry which carries out production based on estimate must determine the volume of production by estimating demand for each product. It is desired that each production instruction volume should be determined based on the estimated profit and the probability of going into the red when production is carried out based on a certain production instruction volume.
Profit must be calculated from many factors such as production volume, demand, production cost, sales and inventory control cost. It is necessary to calculate the production instruction volume of each product so as to maximize the calculated profit and minimize the probability of going into the red. In general, there are many kinds of products and the number of variables used for the calculation of profit is large. Although demand for each product is represented by a random variable, as each of a large number of products has random variables, it is difficult to compute the probability distribution of profit having so many random variables.
It is also desired that a strategy based on the management policy of the manufacturing industry such as a high-risk high-return strategy that return is high though risk is high or a low-risk low-return strategy that return is obtained without fail and risk is low though return is low should be reflected on decisions on amount of the production order.
It is an object of the present invention to enable a user to select the final set of amount of the production order based on his/her management strategy by computing a plurality of sets of amount of the production order in consideration of demand forecast information and outputting profit and risk estimates for each of the sets of amount of the production order.
A plurality of sets of production volume instructions having information for specifying the production volumes of a plurality of products are created, demand for each product is simulated from demand forecast information for each product, evaluation values of a plurality of evaluation indices are computed from demand for each product and the production volume of each product for each set of amount of the production order, and sets of amount of the production order are computed which are inferior to other sets of amount of the production order in some evaluation indices but superior to the other sets of amount of the production order in the other evaluation indices to output a plurality of sets of amount of the production order and a plurality of sets of amount of the production order are displayed so that a user can select one of them.